NAME
Text::Corpus::VoiceOfAmerica - Make a corpus of VOA documents for research.
SYNOPSIS
use Cwd;
use File::Spec;
use Data::Dump qw(dump);
use Log::Log4perl qw(:easy);
use Text::Corpus::VoiceOfAmerica;
Log::Log4perl->easy_init ($INFO);
my $corpusDirectory = File::Spec->catfile (getcwd(), 'corpus_voa');
my $corpus = Text::Corpus::VoiceOfAmerica->new (corpusDirectory => $corpusDirectory);
$corpus->update (testing => 1, verbose => 1);
my $document = $corpus->getDocument (index => 0);
dump $document->getBody;
dump $document->getCategories;
dump $document->getContent;
dump $document->getDate;
dump $document->getDescription;
dump $document->getTitle;
dump $document->getUri;DESCRIPTION
Text::Corpus::VoiceOfAmerica can be used to create a temporary corpus of Voice of America news documents for personal research and testing of information processing methods. Read the Voice of America's Terms of Use statement to ensure you abide by it when using this module.
The categories, description, title, etc... of a specified document are accessed using Text::Corpus::VoiceOfAmerica::Document. Also, all errors and warnings are logged using Log::Log4perl, which should be initialized.
CONSTRUCTOR
new
The constructor new creates an instance of the Text::Corpus::VoiceOfAmerica class with the following parameters:
corpusDirectory-
corpusDirectory => '...'corpusDirectoryis the directory that documents are cached into using CHI. IfcorpusDirectoryis not defined, then the path specified in the environment variableTEXT_CORPUS_VOICEOFAMERICA_CORPUSDIRECTORYis used if it is defined. If the directory defined does not exist, it will be created. A message is logged and an exception is thrown if no directory is specified.
METHODS
getDocument
getDocument (index => $index, cacheOnly => 0)
getDocument (uri => $uri, cacheOnly => 0)getDocument returns a Text::Corpus::VoiceOfAmerica::Document object for the document with index $documentIndex or uri $uri. The document indices range from zero to getTotalDocument()-1; getDocument returns undef if any errors occurred and logs them using Log::Log4perl.
index-
index => '...'indexshould be the number of the document to return. It should be a non-negative integer less thangetTotalDocument. If it is out of rangeundefis returned. uri-
uri => '...'urishould be the URL of the document to return. If the document is not in the cache, it is fetched unlesscacheOnlyevaluates to false, in that caseundefis returned. cacheOnly-
cacheOnly => 0If
cacheOnlyevaluates to true, then only documents in the cache are returned, otherwiseundefis returned. The default is false.
An example:
use Cwd;
use File::Spec;
use Data::Dump qw(dump);
use Log::Log4perl qw(:easy);
use Text::Corpus::VoiceOfAmerica;
Log::Log4perl->easy_init ($INFO);
my $corpusDirectory = File::Spec->catfile (getcwd(), 'corpus_voa');
my $corpus = Text::Corpus::VoiceOfAmerica->new (corpusDirectory => $corpusDirectory);
$corpus->update (testing => 1, verbose => 1);
my $document = $corpus->getDocument (index => 0);
dump $document->getBody;
dump $document->getCategories;
dump $document->getContent;
dump $document->getDate;
dump $document->getDescription;
dump $document->getTitle;
dump $document->getUri;getTotalDocuments
getTotalDocuments ()getTotalDocuments returns the total number of documents in the corpus. The index to the documents in the corpus ranges from zero to getTotalDocuments() - 1.
getURIsInCorpus
getURIsInCorpus ()getURIsInCorpus returns an array reference of all the URIs in the corpus.
For example:
use Cwd;
use File::Spec;
use Data::Dump qw(dump);
use Log::Log4perl qw(:easy);
use Text::Corpus::VoiceOfAmerica;
Log::Log4perl->easy_init ($INFO);
my $corpusDirectory = File::Spec->catfile (getcwd(), 'corpus_voa');
my $corpus = Text::Corpus::VoiceOfAmerica->new (corpusDirectory => $corpusDirectory);
$corpus->update (testing => 1, verbose => 1);
dump $corpus->getURIsInCorpus;update
update (verbose => 0)This method updates the set of documents in the corpus by fetching any newly listed documents in the sitemap.xml file.
verbose-
verbose => 0If
verboseis positive, then after each new document is fetched a message is logged stating the number of documents remaining to fetch and the approximate time to completion.updatereturns the number of documents fetched. testing-
testing => 0If
testingis true, only one document is added to the corpus.
For example:
use Cwd;
use File::Spec;
use Data::Dump qw(dump);
use Log::Log4perl qw(:easy);
use Text::Corpus::VoiceOfAmerica;
Log::Log4perl->easy_init ($INFO);
my $corpusDirectory = File::Spec->catfile (getcwd(), 'corpus_voa');
my $corpus = Text::Corpus::VoiceOfAmerica->new (corpusDirectory => $corpusDirectory);
$corpus->update (testing => 1, verbose => 1);
dump $corpus->getTotalDocuments;EXAMPLES
The example below will print out all the information for each document in the corpus.
use Cwd;
use File::Spec;
use Data::Dump qw(dump);
use Log::Log4perl qw(:easy);
use Text::Corpus::VoiceOfAmerica;
Log::Log4perl->easy_init ($INFO);
my $corpusDirectory = File::Spec->catfile (getcwd(), 'corpus_voa');
my $corpus = Text::Corpus::VoiceOfAmerica->new (corpusDirectory => $corpusDirectory);
$corpus->update (testing => 1, verbose => 1);
my $totalDocuments = $corpus->getTotalDocuments;
for (my $i = 0; $i < $totalDocuments; $i++)
{
eval
{
my $document = $corpus->getDocument(index => $i);
next unless defined $document;
my %documentInfo;
$documentInfo{title} = $document->getTitle();
$documentInfo{body} = $document->getBody();
$documentInfo{date} = $document->getDate();
$documentInfo{content} = $document->getContent();
$documentInfo{categories} = $document->getCategories();
$documentInfo{description} = $document->getDescription();
$documentInfo{uri} = $document->getUri();
dump \%documentInfo;
};
}INSTALLATION
To install the module set TEXT_CORPUS_VOICEOFAMERICA_FULL_TESTING to true and run the following commands:
perl Makefile.PL
make
make test
make installIf you are on a windows box you should use 'nmake' rather than 'make'.
The module will install if TEXT_CORPUS_VOICEOFAMERICA_FULL_TESTING is not defined or false, but little testing will be performed.
BUGS
This module uses xpath expressions to extract links and text which may become invalid as the format of various pages change, causing a lot of bugs.
Please email bugs reports or feature requests to text-corpus-voiceofamerica@rt.cpan.org, or through the web interface at http://rt.cpan.org/Public/Bug/Report.html?Queue=Text-Corpus-VoiceOfAmerica. The author will be notified and you can be automatically notified of progress on the bug fix or feature request.
AUTHOR
Jeff Kubina<jeff.kubina@gmail.com>COPYRIGHT
Copyright (c) 2009 Jeff Kubina. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included with this module.
KEYWORDS
corpus, english corpus, information processing, voa, voice of america